A report by the Urban Green Council released today estimates that poorly fitted window air-conditioners cost buildings in New York City $130 million to $180 million a year in extra fuel consumption, which in turn is linked to an extra 375,000 to 525,000 tons of carbon dioxide emissions, according to an article today in The New York Times by Mireya Navarro.

"While the report covers only New York City buildings," the article said, "the problem extends across the nation, said Russell Unger, executive director of the Urban Green Council, the New York affiliate of the United States Green Building Council. (The national council is best known for bestowing the LEED seal of approval on environmentally friendly buildings.) "

"And while the heat loss matters more in areas with long winters like the Northeast, Mr. Unger said, cool air also leaks out when the units are in use in hot weather, resulting in higher electricity costs," the article continued.

"This is something under everyone's noses, and it's totally overlooked," Mr. Unger said, adding that "it's an issue in every building that doesn't have central air."

The report, titled "There Are Holes in Our City's Walls," is based on tests by Steven Winters Associates, a building-design consulting firm, on three types of units commonly used in the city: the window-mounted air-conditioner that is a fixture of prewar buildings; the air-conditioner that sits in a metal sleeve in the wall; and a packaged-terminal air-conditioner that protrudes into the room and is usually permanently installed at the time of construction.

"In all 11 buildings tested in the city," the article said, "building engineers found that each poorly fitted and poorly sealed unit left a gap equivalent to a hole roughly 2 inches by 3 inches - 'about the size of your fist if you punched a hole in the wall,' as Mr. Unger put it."

In some buildings, the report said, the cost of fuel lost to such energy waste is equal to the total cost of cooling the building alone.

"The report recommends both immediate and long-term steps to deal with the problem," the article said, "including building-wide programs to remove and store the window-mounted units and the manufacturing of improved installation kits for all units. The sleeve models are supposed to stay in place year-round, but they can be winterized to plug holes, the report says. It also counsels against a common practice by many residents: buying cheaper window units instead of the appropriate models to fit into the existing metal sleeves, ensuring a bad fit."

Getting residents to remove window-mounted air-conditioners when they are not in use is a daunting challenge, the report says. One reason is the expense: residents of high-rise buildings are often required to hire professional help to remove and reinstall the units as a safety precaution. Another is lack of storage space, the report noted.

"John H. Slattery, a real estate agent who is treasurer of his Upper East Side co-op building, said that he paid to remove his air-conditioners in the fall," the article said, "but that it had nothing to do with saving energy. 'I take them out because they're ugly, and they rob me of light,' he said. At the same time, Mr. Slattery considers the twice-yearly removal and reinstallation 'a nuisance.'"